Use of a dyestuff for ink jet printing recording materials

ABSTRACT

Disclosed are dyestuff mixtures for printing recording materials, especially textile fibre materials, paper and papery substrates and plastic films and plastic, as well as compositions suitable for ink-jet printing comprising a dyestuff of the formula (I)

The invention relates to novel dyestuff mixtures, the use of such mixtures for printing recording materials, especially paper or papery substrates, textile fibre materials, plastic films and plastic transparencies by the inkjet printing process and also to the recording materials printed thereby.

Inkjet printing processes are becoming more and more important for industrial applications.

Inkjet printing processes are known. In what follows, the principle of inkjet printing will only be discussed very briefly. Details of this technology are described for example in the Ink-Jet-Printing section of R. W. Kenyon in “Chemistry and Technology of Printing and Imaging Systems”, Peter Gregory (editor), Blackie Academic & Professional, Chapmann & Hall 1996, pages 113–138, and references cited therein.

In the inkjet printing process, individual droplets of the ink are sprayed from a nozzle onto a substrate in a controlled manner. The continuous inkjet method and the drop-on-demand method are employed predominantly for this purpose. In the case of the continuous inkjet method, the droplets are produced continuously and droplets not needed for printing are diverted into a collecting vessel and recycled. In the case of the discontinuous drop-on-demand method, by contrast, droplets are generated and printed as desired, i.e. droplets are only generated when this is necessary for printing. The droplets may be generated for example by means of a piezo inkjet head or by means of thermal energy (bubble jet).

By additionally disposing at least one nozzle with yellow, magenta or cyan ink side by side it is possible to obtain colour reproductions in high quality. This process is known as polychromatic printing or, when three colour components are used, as trichromatic printing.

The composition of the invention can be used with all known and suitable inkjet printers for printing paper or papery substrates, textile fibre materials, plastic films and plastic transparencies. This applies not only to the use in monochromatic printing but also to polychromatic printing, especially trichromatic printing.

The composition of the ink for the inkjet printing process has to possess a suitable conductivity, sterility in storage, viscosity and surface tension to meet the specific requirements of inkjet ink. In addition, the prints on the recording materials have to have good properties and fastness.

Useful recording materials, as mentioned above, are preferably paper and papery substrates, textile fibre materials, plastic films and plastic transparencies. But glass and metal may be used as well.

Useful papers or papery substrates include all known such materials. Preference is given to papers or papery substrates coated on at least one side with a material which is particularly receptive to ink compositions. Such papers or papery materials are described inter alia in DE 3018342, DE 4446551, EP 164196 and EP 875393.

Useful textile fibre materials are in particular hydroxyl-containing fibre materials. Preference is given to cellulosic fibre materials, which consist of or comprise cellulose. Examples are natural fibre materials such as cotton, linen or hemp and regenerated fibre materials such as, for example, viscose and also lyocell.

Useful plastic films or plastic transparencies include all known such materials. Preference is given to plastic films or plastic transparencies coated on at least one side with a material which is particularly receptive to the ink compositions. Such plastic films or plastic transparencies are described inter alia in EP 755332, U.S. Pat. No. 4,935,307, U.S. Pat. No. 4,956,320, U.S. Pat. No. 5,134,198 and U.S. Pat. No. 5,219,928.

This invention provides a inkjet printing composition for printing recording materials by comprising

-   -   1) the dye of formula (I)

-   -    and     -   2) water or a medium including a mixture of water and an organic         solvent, an anhydrous organic solvent or a solid having a low         melting point,

There may be optionally further additives be present in the composition according to the invention as described below.

The invention further provides the use of a compound of formula (I)

for ink jet printing or the use of a compound of formula (I) in ink jet printing compositions. The invention further provides the use of a compound of formula (I) for ink jet printing or for electrophotographic printing. The invention further provides toners for electrophotographic printing comprising a compound of formula (I).

This invention further provides dyestuff mixtures comprising at least compound of formula (I)

as free acid or in salt form and at least one compound according to formula (II) and/or formula (III) and/or formula (IV) and/or formula (V) wherein the compounds of formulas (II) signifies

wherein

-   R₇ and R′₇ signify independently from each other H or halogen, -   R₈ signifies —OH or NR₁₆R₁₇, wherein     -   R₁₆ signifies H; unsubstituted C₁₋₄alkyl; substituted C₁₋₄alkyl;         unsubstituted phenyl or a substituted phenyl,     -   R₁₇ signifies unsubstituted C₁₋₄alkyl; substituted C₁₋₄alkyl;         unsubstituted phenyl or a substituted phenyl, -   R₉ signifies O or NR₁₇, wherein     -   R₁₇ has the same meanings as defined above, -   R₁₀ and R′₁₀ signify independently from each other H; halogen;     unsubstituted C₁₋₂alkyl or —NO₂, -   R₁₁ signifies —SO₃H or —COOH, -   R₁₂ signifies H or halogen, -   R₁₃ signifies H; —SO₃H or halogen -   R₁₄ signifies H or halogen, -   R₁₅ signifies H or halogen,     wherein the compounds of formulas (III) signifies

wherein

-   R₁₈ signifies H;

-    —COC₁₋₂alkyl; —CO(CH₂O)_(n)—R₂₂; —SO₂R₂₂,     -   wherein     -   R₂₂ signifies an unsubstituted phenyl or a phenyl moiety, which         is substituted by at least one substituent of the group         consisting of —CH₃ or halogen,     -   n is 0 or 1, -   R₁₉ signifies H; —CH₃; —SO₃H or —OR₂₃, wherein     -   R₂₃ signifies —CH₃; unsubstituted phenyl; substituted phenyl or         benzyl -   R₂₀ signifies H; halogen; C₁₋₁₀alkyl or —NHCOCHBrCH₂Br -   R₂₁ signifies H; —NO₂; C₁₋₁₅alkyl or C₅₋₇cycloalkyl;     wherein the compounds of formulas (IV) signifies

wherein

-   R₂₄ signifies H or —SO₃H, -   R₂₅ signifies H; —NHCOC₁₋₂alkyl or —OH, -   R₂₆ signifies H or —OH; -   R₂₇ signifies

-    wherein     -   R₂₈ signifies H or unsubstituted phenyl,     -   R₂₉ signifies H; —COH; —NO₂;

-    wherein     -   R₃₀ is H or —CH₃, or -   R₂₇ signifies

wherein the compounds of formulas (V) signifies

wherein

-   R₃₁ signifies H or

-   R₃₂ signifies

wherein

-   R₃₃ signifies H; —SO₃H; —CF₃; —Cl; —COOC₁₋₂alkyl; —SO₂R₃₆, wherein     -   R₃₆ signifies unsubstituted phenyl; substituted phenyl;         O-phenyl; —NH—C₁₋₁₂alkyl; —N(C₁₋₆alkyl)₂; unsubstituted         C₅₋₈cycloalkyl; substituted C₅₋₈cycloalkyl; C₅₋₈cycloalkyl with         at least one N, O or S atom incorporated into the ring;

-   R₃₄ signifies H; —NHCOC₁₋₄alkyl; —NHCOphenyl, wherein the phenyl     ring can be unsubstituted or substituted; —N(C₁₋₂alkyl)COC₁₋₄alkyl;     —N(C₁₋₂alkyl)COphenyl, wherein the phenyl ring can be unsubstituted     or substituted; unsubstituted phenyl; substituted phenyl; O-phenyl,     wherein the phenyl can be unsubstituted or substituted; halogen;     —SO₃H; —NHCOOC₁₋₂alkyl; —NHCOOC₅₋₇cycloalkyl, wherein the cycloalkyl     can be substituted or unsubstituted and —SO₂NHphenyl, wherein the     phenyl ring can be unsubstituted or substituted, -   R₃₅ signifies H; —NHCOC₁₋₄alkyl; —NHCOphenyl, wherein the phenyl     ring can be unsubstituted or substituted; —N(C₁₋₂alkyl)COC₁₋₄alkyl;     —N(C₁₋₂alkyl)COphenyl, wherein the phenyl ring can be unsubstituted     or substituted; unsubstituted phenyl; substituted phenyl; O-phenyl,     wherein the phenyl can be unsubstituted or substituted; halogen;     —Cl; —CH₃; —COOC₁₋₄alkyl and —SO₂NHphenyl, wherein the phenyl ring     can be unsubstituted or substituted.

Any alkyl or alkylene group may be linear or branched.

Useful cations for salt formation include in particular alkali metal, alkaline earth metal as well ammonium cations. Examples of such cations are alkali metal cations, for example potassium, lithium or sodium ions and ammonium cations, e.g. mono-, di-, tri- or tetra-methyl ammonium cations or mono-, di-, tri- or tetra-ethyl ammonium cations or mono-, di- or tri-ethanol ammonium cations. The cations may be the same or different, i.e. the compounds may be in mixed salt-form.

Preferred compounds according to formula (II) are C.I. (Colour Index) Acid Red 50, C.I. Acid Red 51, C.I. Acid Red 52, C.I. Acid Red 87, C.I. Acid Red 91, C.I. Acid Red 92, C.I. Acid Red 93, C.I. Acid Red 94, C.I. Acid Red 95, C.I. Acid Red 98, C.I. Acid Red 289, C.I. Acid Violet 9 or C.I. Acid Violet 30 and

-   preferred compounds according to formula (III) are C.I. Acid Red 1,     C.I. Acid Red 33, C.I. Acid Red 35, C.I. Acid Red 40, C.I. Acid Red     76, C.I. Acid Red 106, C.I. Acid Red 138, C.I. Acid Red 155, C.I.     Acid Red 160, C.I. Acid Red 172, C.I. Acid Red 249, C.I. Acid Red     264 or C.I. Acid Red 265, and -   preferred compounds according to formula (IV) are C.I. Acid Red 15,     C.I. Acid Red 19, C.I. Acid Red 29, C.I. Acid Red 60, C.I. Acid Red     68, C.I. Acid Red 154 or C.I. Acid Red 176 and -   preferred compounds according to formula (V) are C.I. Acid Red 30,     C.I. Acid Red 34, C.I. Acid Red 37, C.I. Acid Red 42, C.I. Acid Red     54, C.I. Acid Red 57, C.I. Acid Red 231, C.I. Acid Red 266, C.I.     Acid Red 301 or C.I. Acid Red 337

Especially preferred mixture comprises a compound according to formula (Ie) and C.I. Acid Red 52 and/or C.I. Acid Red 289 which have the following formulae

respectively.

It is possible to use the dyestuff (I) without any further dyestuff in the composition Ink jet printing compositions according the present invention.

A further embodiment of the present invention relates to a composition for printing recording materials, preferably paper and papery substrates, textile fibre materials, plastic films and plastic transparencies by the inkjet printing process, comprising

-   1) the dye of the formula (I) as defined above and -   2) water or a medium including a mixture of water and an organic     solvent, an anhydrous organic solvent or a solid having a low     melting point,     The inkjet printing composition may optionally comprise further     additives.

A further embodiment of the present invention relates to a inkjet printing composition for printing recording materials, preferably paper and papery substrates, textile fibre materials, plastic films and plastic transparencies, comprising

-   1) a mixture of dyestuffs as defined above and -   2) water or a medium including a mixture of water and an organic     solvent, an anhydrous organic solvent or a solid having a low     melting point,     The inkjet printing composition may optionally comprise further     additives.

When dyestuff mixture are used a dyestuff mixture according to the present invention preferably comprises

-   50–99 wt-% of at least one compound according to formula (I) and -   1–50 wt-% of at least one compound according to formula (II) and/or     at least one compound according to formula (III) and/or at least one     compound according to formula (IV) and/or at least one compound     according to formula (V).     The weight percentages are related to the total amount of dyestuff     and wherein the sum of the weight percentages is always 100.

A further embodiment of the invention relates to the use of the above mentioned compositions for the ink-jet printing process.

The dyes of the formula (I), (II), (III), (IV) and/or (V) in the used in the inks should preferably be low in salt, i.e. have a total salt content of less than 0.5% by weight, based on the weight of the dyes. Dyes having higher salt contents (owing to their preparation and/or the subsequent addition of extenders) may be desalted, for example by means of membrane separation processes, such as ultrafiltration, reverse osmosis or dialysis.

The inks preferably include a total amount of dyes which is in the range from 0.5 to 35% by weight, preferably in the range from 1 to 35% by weight, more preferably in the range from 2 to 30% by weight, most preferably in the range from 2.5 to 20% by weight, based on the total weight of the ink.

The inks include 99.5–65% by weight, preferably 99–65% by weight, more preferably 98–70% by weight, most preferably 97.5–80% by weight, of an above-mentioned medium 2), which includes a mixture of water and an organic solvent, an anhydrous organic solvent or a solid having a low melting point.

When said medium 2) is a mixture including water and an organic solvent or an anhydrous organic solvent, the dye mixtures comprising at least one compounds of formula (I) and at least one compound of formula (II) and/or at least one compounds of formula (III) and/or at least one compound of formula (IV) and/or at least one compound of formula (V) are preferably completely dissolved in this medium.

Preferably the dye mixtures comprising at least one compounds of formula (I) and at least one compound of formula (II) and/or at least one compounds of formula (III) and/or at least one compound of formula (IV) and/or at least one compound of formula (V) as well as the new compounds according to formula (I) have a solubility of not less than 2.5% by weight in this medium 2) at 20° C.

When the ink composition of the invention is used for printing paper or papery substrates, the inks are preferably used together with the following compositions. When the medium is a mixture of water and an organic solvent, the weight ratio of water to organic solvent is preferably in the range from 99:1 to 1:99, more preferably in the range from 99:1 to 50:50, particularly preferably in the range from 95:5 to 80:20.

It is preferable for the organic solvent, which is included in the mixture with water to be a water-soluble solvent or a mixture of various water-soluble solvents. Preferred water-soluble organic solvents are C₁₋₆-alcohols, preferably methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, n-pentanol, cyclopentanol and cyclohexanol; linear amides, preferably dimethylformamide, or dimethylacetamide; ketones and keto alcohols, preferably acetone, methyl ethyl ketone, cyclohexanone and diacetone alcohol; water-miscible ethers, preferably tetrahydrofuran and dioxane; diols, preferably diols possessing 2 to 12 carbon atoms, e.g. 1,5-pentanediol, ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol and thiodiglycol and oligo- and poly-alkylene glycols, preferably diethylene glycol, triethylene glycol, 1,2-propylenglycol, polyethylene glycol and polypropylene glycol; triols, preferably glycerol and 1,2,6-hexanetriol; mono-C₁₋₄-alkyl ethers of diols, preferably mono-C₁₋₄-alkyl ethers of diols possessing 2 to 12 carbon atoms, particularly preferably 2-methoxyethanol, 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)ethanol, 2-[2-(2-methoxyethoxy)ethoxy]-ethanol, 2-[2-(2-ethoxyethoxy)ethoxy]ethanol, diethylenglycol-mono-n-butylether, ethylene glycol monoallyl ether and polyoxyethylenalkylether (for example Emulgen 66 of KAO Corp. (Emulgen is a trade mark of the Kao Corp.)); alkanolamines, preferably 2-diethylamine-1-ethanol, 3-dimethylamine-1-propanol, 3-diethylamine-1-propanol, 2-(2-aminoethoxy)ethanol, 2-(2-dimethylaminoethoxy)-ethanol, 2-(2-diethylaminoethoxy)ethanol, mono-, di-, triethanolamine, monoglycolamines and polyglycolamines, which may be obtained by reaction of ammonia, alkyl- or hydroxyalkylamines like methylamine, ethylamine, dimethylaamine, diethylamine, mono-, di- and triethanolamines with alkyleneoxides for example ethylenoxide, 1,2-propylenoxide, 1,2-butylenoxide or 2,3-butylenoxide in suitable ratios as described in DE2061760A, preferably diethylenglycolamine, triethylenglycolamin, Bis-diethylenglycolamin, polyoxyethylen-(6)-triethanolamine, polyoxyethylen-(9)-triethanolamine, o-(2-aminoethyl)-polyethylenglycol 750, o,o-Bis-(2-aminopropyl)-polyethylenglycol 500, 800, 1900, 2000, o,o′-Bis-(3-aminopropyl)-polyethylenglycol 1500, cyclic amides, preferably 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-(2-hydroxy)ethyl-2-pyrrolidone, caprolactam and 1,3-dimethylimidazolidone; cyclic esters, preferably caprolactone; sulphoxides, preferably dimethyl sulphoxide and sulpholane.

In a preferred composition, the medium as per 2) includes water and at least 2 or more, more preferably 2 to 8, water-soluble organic solvents.

Particularly preferred water-soluble solvents are cyclic amides, particularly 2-pyrrolidone, N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone; N-(2-hydroxy)ethyl-2-pyrrolidone, C₁₋₆-alcohols, preferably n-propanol, cyclohexanol, diols, preferably 1,5-pentanediol, ethylene glycol, thiodiglycol, diethylene glycol, triethylene glycol and 1,2-propyleneglycol, triols, preferably glycerol; and mono-C₁₋₄-alkyl and C₁₋₄-alkyl ethers of diols, more preferably mono-C₁₋₄-alkyl ethers of diols possessing 2 to 12 carbon atoms, particularly preferably 2-[2-(2-methoxyethoxy)-ethoxy]-ethanol, diethylenglycol-mono-n-butylether, (for example Emulgen 66 of KAO Corp. (Emulgen is a trade mark of the Kao Corp.)), 2-diethylamine-1-ethanol, 3-dimethylamine-1-propanol, 3-diethylamine-1-propanol, 2-(2-diethylaminoethoxy)-ethanol, triethanolamine, diethylenglycolamin, polyglycolamines, preferably polyoyxethylen-(6)-triethanolamin, polyoxyethylen-(9)-triethanolamine, o-(2-aminoethyl)-polyethylen 750, o,o-bis-(2-aminopropyl)-poyethylen 500 and o,o-bis-(3-aminopropyl)-polyethylenglycol 1500.

A preferred medium as per 2) comprises

-   -   (a) 75 to 95 parts by weight of water and     -   (b) 25 to 5 parts of one or more of the watersoluble solvents.         wherein the parts are by weight and all parts of (a) and (b) add         up to 100.

Examples of further useful ink compositions including water and one or more organic solvents are found in the Patent Specifications U.S. Pat. No. 4,963,189, U.S. Pat. No. 4,703,113, U.S. Pat. No. 4,626,284 and EP 425150A.

When the medium as per 2) includes an anhydrous (i.e. less than 1% by weight of water) organic solvent, this solvent will have a boiling point of 30 to 200° C., more preferably of 40–150° C., particularly preferably of 50–125° C.

The organic solvent can be water-insoluble, water-soluble or mixtures of such solvents.

Preferred water-soluble organic solvents are all above-described water-soluble organic solvents and mixtures thereof.

Preferred water-insoluble solvents include inter alia aliphatic hydrocarbons; esters, preferably ethyl acetate; chlorinated hydrocarbons, preferably CH₂Cl₂; and ethers, preferably diethyl ether; and mixtures thereof.

When the liquid medium as per 2) includes a water-insoluble organic solvent, it is preferable to add a polar solvent to increase the solubility of the dye in the liquid medium.

Examples of such polar solvents are C₁₋₄-alcohols, preferably ethanol or propanol; ketones, preferably methyl ethyl ketone.

The anhydrous organic solvent can consist of a single solvent or a mixture of 2 or more different solvents.

When it is a mixture of different solvents, a mixture including 2 to 5 different anhydrous solvents is preferred. This makes it possible to provide a medium as per 2) which permits good control of the drying properties and of the stability of the ink composition in storage.

Ink compositions including an anhydrous organic solvent or mixtures thereof are of particular interest when rapid drying times are required and especially when they are used for prints on hydrophobic and non-absorbing substrates, such as plastic, metal and glass.

Preferred low-melting media have a melting point of 60 to 125° C. Useful low-melting solids include long-chain fatty acids or alcohols, preferably those having a C₁₈₋₂₄-carbon chain, and sulphonamides.

The ink composition of the invention may further include as auxiliaries additional components which are normally used in inkjet inks, for example viscosity improvers, surface tension improvers, biocides, corrosion inhibitors, levelling agents, drying agents, humefactants, ink penetration additives, light stabilizers, UV absorbers, optical brighteners, coagulation reducers, ionic or nonionic surfactants, conducting salts and pH buffers.

These auxiliaries are preferably added in an amount of 0–5% by weight.

To prevent precipitation in the ink compositions of the invention, the dyes used have to be purified clean. This can be done with commonly known purifying methods.

When printing textile fibre materials, useful additives, as well as the solvents, include water-soluble nonionic cellulose ethers or alginates.

The preferred material is paper. The paper may be plain or treated.

Preference is given to ink compositions having a viscosity of 1 to 40 mPa·s, especially 5 to 40 mPa·s, preferably 10 to 40 mPa·s. Ink compositions having a viscosity of 10 to 35 mPa·s are particularly preferred.

Preference is given to ink compositions having a surface tension of 15–73 mN/m, especially 20–65 mN/m, particularly preferably 30–50 mN/m.

Preference is given to ink compositions having a conductivity of 0.1–100 mS/cm, especially 0.5–70 mS/cm, particularly preferably 1.0–60 mS/cm.

The inks may further include buffer substances, for example borax, borate or citrate. Examples are sodium borate, sodium tetraborate and sodium citrate.

They are used in particular in amounts of 0.1 to 3% by weight, preferably 0.1 to 1% by weight, based on the total weight of the ink, to set a pH of for example 5 to 9, especially 6 to 8. A citrate buffer is preferred in the case of alginatic inks.

The inks may further include customary additives, for example foam suppressants or especially fungal and/or bacterial growth inhibitors. These are customarily used in amounts of 0.01 to 1% by weight, based on the total weight of the ink.

The printing inks and also the dye mixtures comprising comprising at least the compound of formula (I) and at least one further compound selected from the compounds of formula (II), (III), (IV) and/or (V).

The prints obtainable by the process of the invention have good general fastnesses, a good lightfastness and also sharp contours and a high colour strength. The inks provide prints of high optical density.

The printing inks used are notable for good stability and good viscosity properties. The recording fluids of the invention have viscosity and surface tension values which are within the ranges suitable for the ink-jet processes. The viscosity remains virtually unchanged even in the event of high shearing forces occurring during printing.

Recording fluids according to the invention in storage are not prone to the formation of precipitates that leads to fuzzy prints or nozzle cloggage.

A further aspect of the present invention is the use of the printing ink in trichromatic printing. Trichromatic printing is a very large application for all recording materials. This form of printing is normally carried out with a yellow, red and blue ink composition. Furthermore, the magenta dye mixtures of the invention may be used as an ink set in combination with black, yellow and/or cyan recording fluids.

The dyestuff mixtures according to the invention may be used for shading other dystuffs or dyestuff mixtures. While the mixtures according to the invention itself may be blended with other compabibles dyestuff mixtures to achieve the desired shade. Instead of blending the dystuff mixtures it is also possible to mix inks of different shades to achieve the desired colour.

For example the shading colorant may be selected (among others) from the group consisting of C.I. Direct Red 1, 11, 37, 62, 75, 81, 87, 89, 95, 227; C.I. Acid Red 115, 131, 144, 152, 186, 245, C.I. Pigment Red 122, 176, 184, 185 and 269. The shading colorants are present in an amount of 0.001 to 5% by weight, preferably 0.01 to 1% by weight, based on the total weight of the dry dye mixture.

This invention further provides recording materials, which have been printed with a composition according to the invention.

Moreover, the dye mixtures of the invention are useful as colorants in the electrophotographic toners and developers, for example one- and two-component powder toners, magnetic toners, liquid toners, polymerization toners and other specialty toners.

Typical toner binders are addition polymerization, polyaddition and polycondensation resins, such as styrene, styrene-acrylate, styrene-butadiene, acrylate, polyester, phenolic and epoxy resins, polysulfones, polyurethanes, individually or in combination, and also polyethylene and polypropylene, in or to which further ingredients, such as charge control agents, waxes or flow agents, may be present or added subsequently. Dye mixtures according to the invention are further useful as colorants in powders and powder coating materials, especially triboelectrically or electrostatically sprayed powder coating materials, which are used to coat the surfaces of articles made for example of metal, wood, plastic, glass, ceramic, concrete, textile material, paper or rubber. Powder coating resins employed are typically epoxy resins, carboxyl- and hydroxyl-containing polyester resins, polyurethane resins and acrylic resins together with customary curing agents. Combinations of resins are also used. For instance, epoxy resins are frequently used in combination with carboxyl- and hydroxyl-containing polyester resins.

The dye mixtures of the invention are also useful as colorants for color filters, for additive as well as subtractive color generation (P. Gregory “Topics in Applied Chemistry: High Technology Applications of Organic Colorants” Plenum Press, New York 1991, page 15-25), and also as colorants in electronic inks for electronic newspapers.

The examples hereinbelow illustrate the invention. Temperatures are in degrees Celsius; parts and percentages are by weight, unless otherwise stated.

Examples of Ink Compositions:

A preferred ink composition according to the invention comprises

0.5–35 parts of a of formula (I), 65–99.5 parts of water or a medium including a mixture of water and an organic solvent, an anhydrous organic solvent or a solid having a low melting point and optionally 0–5 parts of one or more additives.

A more preferred ink composition according to the invention comprises

1–20 parts of a of formula (I), 80–99 parts of water or a medium including a mixture of water and an organic solvent, an anhydrous organic solvent or a solid having a low melting point and optionally 0–5 parts of one or more additives.

A particularly preferred ink composition according to the invention comprises

1–5 parts of a of formula (I), 95–99 parts of water or a medium including a mixture of water and an organic solvent, an anhydrous organic solvent or a solid having a low melting point and optionally 0–5 parts of one or more additives.

A more preferred ink composition according to the invention comprises

0.5–35 parts of a dye mixtures comprising at least one compound of formula (I) and at least one compound of formula (II), (III), (IV) and/or (V), 65–99.5 parts of water or a medium including a mixture of water and an organic solvent, an anhydrous organic solvent or a solid having a low melting point and optionally 0–5 parts of one or more additives.

A particularly preferred ink composition according to the invention comprises

1–2 parts of a dye mixtures comprising at least one compound of formula (I) and at least one compound of formula (II), (III), (IV) and/or (V), 80–99 parts of water or a medium including a mixture of water and an organic solvent, an anhydrous organic solvent or a solid having a low melting point and optionally 0–5 parts of one or more additives.

A further preferred ink composition according to the invention comprises

1–5 parts of a dye mixtures comprising at least one compound of formula (I) and at least one compound of formula (II), (III), (IV) and/or (V), and 95–99 parts of water or a medium including a mixture of water and an organic solvent, an anhydrous organic solvent or a solid having a low melting point and optionally 0–5 parts of one or more additives.

The sum total of all the parts of the above mentioned compositions according to the invention is 100 parts.

The above mentioned composition is preferably prepared by heating the medium to 40° C. and then adding a dye mixtures comprising at least one compound of formula (Ie) and at least one compound of formula (II), (III), (IV) and/or (V), The composition is then cooled down to room temperature.

This ink composition is preferably used for printing papers or papery substrates.

The following Examples further serve to illustrate the invention, without restricting the scope of protection to these Examples. In the Examples all parts and all percentages are by weight, and the temperatures given are in degrees Celsius, unless indicated to the contrary.

EXAMPLE 1

a) Diazotization and Coupling

46 g (0.2 mol) 1-acetylamino-4-aminobenzene-3-sulfonic acid are diazotized indirectly in 300 ml water. The reaction solution is added to a suspension of 63.8 g (0.2 mol) 2-amino-8-hydroxynaphthalin-3,6-disulfonic acid in 500 ml water at 5° C. The pH-value is adjusted to 2.5–4 by adding sodiumacetate-solution. After the termination of this reaction the compound of formula (I)

is filtered off. b) Isolation

The presscake of a) is washed with brine, until the filtrate becomes clear. After dissolving the presscake in demineralised water of alkalinic pH and desalting by membran filtration, the concetrated solution was dried and the residue milled to powder.

c) Formulation

The powder was dissolved in water at 20° C. to 40° C. and all ingredients were added to obtain the following ink:

2.5 wt % of dyestuff I 15 wt % of N-methyl-2-pyrrolidone 82.5 wt % of water

The ink of example 1 comprising the dyestuff (I) was filtered by micro-filtration (having 0.45 micrometer pores) and was ready to use for ink jet printing.

The following formulations are used for printing materials as described above. Such compositions were made by the same procedure as described in example 1) part c) but by using the dyestuff (I) previously purified by the method of described in example 1) part c) and further ingredients as indicated in the following examples:

EXAMPLE 2

2.5 wt % of dyestuff I 15 wt % of diethylenglycol 82.5 wt % of water

EXAMPLE 3

2.5 wt % of dyestuff I 10 wt % of diethylenglycol 5 wt % of N-methyl-2-pyrrolidone 82.5 wt % of water

EXAMPLE 4

2.5 wt % of dyestuff I 10 wt % of thiodiglycol 5 wt % of N-methyl-2-pyrrolidone 82.5 wt % of water

EXAMPLE 5

2.5 wt % of dyestuff I 5 wt % of glycerol 5 wt % of diethylenglycol 2 wt % of triethanolamine 85.5 wt % of water

EXAMPLE 6

2.5 wt % of dyestuff I 10 wt % of diethylenglycol 1 wt % of Emulgen 66 86.5 wt % of water

EXAMPLE 7

2.5 wt % of dyestuff I 10 wt % of diethylenglycol 3 wt % of diethylenglycol-mono-n-butylether 84.5 wt % of water Dyestuff Mixtures

90 wt-% of the compound of formula (I)

and 10 wt-% of C.I. Acid Red 52. The dyestuffs used were previousely purified by desalting by membran filtration. The inks of the following Examples 8 to 12 were made by the same procedure as described in example 1) part c) but using the further ingredients as indicated in the following examples:

EXAMPLE 8

2.5 wt-% of dyestuff Mixture 1 15 wt-% of N-methyl-2-pyrrolidone 82.5 wt-% of water.

EXAMPLE 9

2.5 wt-% of dyestuff Mixture 1 20 wt-% of 1,2 propyleneglycol 77.5 wt-% of water.

EXAMPLE 10

2.5 wt % of dyestuff mixture 1 8 wt % of diethylenglycol 5 wt % of glycerol 1 wt % of Emulgen 66 83.5 wt % of water

EXAMPLE 11

2.5 wt % of dyestuff mixture 1 5 wt % of diethylenglycolamine 5 wt % of glycerol 87.5 wt % of water

EXAMPLE 12

2.5 wt % of dyestuff mixture 1 10 wt % of thiodiglycol 5 wt % of diethylenglycol 82.5 wt % of water

Purrified dyestuff were milled to powder mixed to the following ratios as indicated in the dyestuff-mixtures 2–17.

TABLE 1 (dyestuff-mixtures 2–17) wt-% of wt-% of Mix. Compound 1 Compound 1 Compound 2 Compound 2 2 Compound of 95 C.I. Acid Red 52 5 formula (I) 3 Compound of 80 C.I. Acid Red 52 20 formula (I) 4 Compound of 70 C.I. Acid Red 52 30 formula I 5 Compound of 95 C.I. Acid Red 289 5 formula (I) 6 Compound of 80 C.I. Acid Red 289 20 formula (I) 7 Compound of 70 C.I. Acid Red 289 30 formula (I) 8 Compound of 95 C.I. Acid Red 1 5 formula (I) 9 Compound of 85 C.I. Acid Red 1 15 formula (I) 10 Compound of 95 C.I. Acid Red 60 5 formula (I) 11 Compound of 85 C.I. Acid Red 60 15 formula (I) 12 Compound of 95 C.I. Acid Red 30 5 formula (I) 13 Compound of 90 C.I. Acid Red 30 10 formula (I) 14 Compound of 80 C.I. Acid Red 30 20 formula (I) 15 Compound of 95 C.I. Acid Red 37 5 formula (I) 16 Compound of 90 C.I. Acid Red 37 10 formula (I) 17 Compound of 80 C.I. Acid Red 37 20 formula (I)

The inks of the following Examples 13 to 42 were made by the same procedure as described in example 1) part c) but using the further ingredients as:

EXAMPLE 13

2.5 wt % of dyestuff mixture 2 10 wt % of diethylenglycol 5 wt % of 1-propanol 82.5 wt % of water

EXAMPLE 14

2.5 wt % of dyestuff mixture 2 8 wt % of diethylenglycol 4 wt % of diethylenglycol-mono-n-butylether 3 wt % of 1-propanol 82.5 wt % of water

EXAMPLE 15

2.5 wt % of dyestuff mixture 2 10 wt % of ethylenglycol 5 wt % of N-methyl-2-pyrrolidon 82.5 wt % of water

EXAMPLE 16

2.5 wt % of dyestuff mixture 3 15 wt % of polyethoxylated-(9)-triethanolamine 82.5 wt % of water

EXAMPLE 17

2.5 wt % of dyestuff mixture 3 15 wt % of diethylenglycol 82.5 wt % of water

EXAMPLE 18

2.5 wt % of dyestuff mixture 3 10 wt % of diethylenglycol 1 wt % of Emulgen 66 86.5 wt % of water

EXAMPLE 19

2.5 wt % of dyestuff mixture 4 15 wt % of polyethoxylated-(6)-triethanolamine 82.5 wt % of water

EXAMPLE 20

2.5 wt % of dyestuff mixture 4 10 wt % of thiodiglycol 5 wt % of diethylenglycol 82.5 wt % of water

EXAMPLE 21

2.5 wt % of dyestuff mixture 4 10 wt % of triethylenglycol 5 wt % of 1-propanol 82.5 wt % of water

EXAMPLE 22

2.5 wt % of dyestuff mixture 4 10 wt % of 1,5-pentanediol 5 wt % of diethylenglycol 82.5 wt % of water

EXAMPLE 23

2.5 wt % of dyestuff mixture 5 15 wt % of 2-[2-(2-methoxyethoxy)ethoxy]-ethanol 82.5 wt % of water

EXAMPLE 24

 2.5 wt % of dyestuff mixture 5   15 wt % of N-(2-hydroxy)ethyl-2-pyrrolidon 82.5 wt % of water

EXAMPLE 25

 2.5 wt % of dyestuff mixture 5   10 wt % of 2-diethylamino-1-ethanol   5 wt % of o,o-bis-(2-aminopropyl)-polyethylenglycol 500 82.5 wt % of water

EXAMPLE 26

 2.5 wt % of dyestuff mixture 6   15 wt % of diethylenglycol 82.5 wt % of water

EXAMPLE 27

 2.5 wt % of dyestuff mixture 6   10 wt % of N-ethyl-2-pyrrolidone   3 wt % of triethanolamine 84.5 wt % of water

EXAMPLE 28

 2.5 wt % of dyestuff mixture 6   10 wt % of o-(2-aminoethyl)-polyethylenglycol 750   5 wt % of thiodiglycol 82.5 wt % of water

EXAMPLE 29

 2.5 wt % of dyestuff mixture 6   10 wt % of 3-dimethylamine-1-propanol   5 wt % of glycerol 82.5 wt % of water

EXAMPLE 30

 2.5 wt % of dyestuff mixture 7   10 wt % of N-methyl-2-pyrrolidon   1 wt % of Emulgen 66 86.5 wt % of water

EXAMPLE 31

 2.5 wt % of dyestuff mixture 7   10 wt % of diethylenglycol   1 wt % of Emulgen 66 86.5 wt % of water

EXAMPLE 32

 2.5 wt % of dyestuff mixture 7   10 wt % of diethylenglycol   5 wt % of cyclohexanol 82.5 wt % of water

EXAMPLE 33

 2.5 wt % of dyestuff mixture 8   10 wt % of diethylenglycol   5 wt % of polyoxyethylen-(9)-triethanolamin 82.5 wt % of water

EXAMPLE 34

 2.5 wt % of dyestuff mixture 9   10 wt % of 1,5-pentanediol   5 wt % of glycerol 82.5 wt % of water

EXAMPLE 35

 2.5 wt % of dyestuff mixture 10   10 wt % of triethanolamine   1 wt % of Emulgen 66 86.5 wt % of water

EXAMPLE 36

 2.5 wt % of dyestuff mixture 11   10 wt % of diethylenglycol   5 wt % of o,o-bis-(3-aminopropyl)-polyethylenglycol 1500 82.5 wt % of water

EXAMPLE 37

 2.5 wt % of dyestuff mixture 12   10 wt % of Polyoxyethylen-(6)-triethanolamine   5 wt % of 1-Propanol 82.5 wt % of water

EXAMPLE 38

 2.5 wt % of dyestuff mixture 13   15 wt % of diethylenglycol 82.5 wt % of water

EXAMPLE 39

 2.5 wt % of dyestuff mixture 14   10 wt % of diethylenglycol   1 wt % of Emulgen 66 86.5 wt % of water

EXAMPLE 40

 2.5 wt % of dyestuff mixture 15   15 wt % of 3-diethylamine-1-propanol 82.5 wt % of water

EXAMPLE 41

 2.5 wt % of dyestuff mixture 16   10 wt % of thiodiglycol   5 wt % of diethylenglycol 82.5 wt % of water

EXAMPLE 42

 2.5 wt % of dyestuff mixture 17   10 wt % of 2-(2-diethylaminoethoxy)-ethanol   5 wt % of diethylenglycol 82.5 wt % of water

APPLICATION EXAMPLES

An ink as indicated above was introduced into an HP 880C DeskJet Printer and printed onto an A4 HP Premium Inkjet paper (HP and DeskJet are registered trademarks of Hewlett-Packard, Palo Alto, Calif., USA). Different properties of the prints have been tested which results are listed next to the ink compositions (Table 2). In the last coloum (with the asterix ^((*))) the difference of the resulting shade when printed is given relative to the Application Examples A-I to A-III which are magenta.

TABLE 2 (Application examples A-I to A-XXVII) Ink- difference Application Example preparation lightfastness brilliance waterfastness of shade^((*)) A-I Example 1 excellent excellent very good A-II Example 2 excellent excellent very good A-III Example 6 excellent excellent very good A-IV Example 8 very good excellent very good more bluish A-V Example 10 very good excellent very good more bluish A-VI Example 13 excellent excellent very good more bluish A-VII Example 15 excellent excellent very good more bluish A-VIII Example 16 good excellent very good more bluish A-IX Example 18 good excellent very good more bluish A-X Example 19 moderate excellent very good more bluish A-XI Example 20 moderate excellent very good more bluish A-XII Example 23 excellent excellent very good more bluish A-XIII Example 24 excellent excellent very good more bluish A-XIV Example 28 good excellent very good more bluish A-XV Example 29 good excellent very good more bluish A-XVI Example 30 moderate excellent very good more bluish A-XVII Example 32 moderate excellent very good more bluish A-XVIII Example 33 excellent good very good more bluish A-XIX Example 34 very good good very good more bluish A-XX Example 35 very good good very good more bluish A-XXI Example 36 good good very good more bluish A-XXII Example 37 very good good very good more yellowish A-XXIII Example 38 very good good very good more yellowish A-XXIV Example 39 very good good very good more yellowish A-XXV Example 40 excellent good very good more yellowish A-XXVI Example 41 excellent good very good more yellowish A-XXVII Example 42 excellent good very good more yellowish 

1. A dyestuff mixture comprising at least one compound of formula (I)

as free acid or in salt form and at least one compound selected from the group consisting of formula (II), formula (III), formula (IV), and formula (V) wherein the compound of formula (II) is

wherein R₇ and R′₇ are independently from each other H or halogen, R₈ is —OH or NR₁₆R₁₇, wherein R₁₆ is H; unsubstituted C₁₋₄alkyl; substituted C₁₋₄alkyl; unsubstituted phenyl or a substituted phenyl, R₁₇ is unsubstituted C₁₋₄alkyl; substituted C₁₋₄alkyl; unsubstituted phenyl or a substituted phenyl, R₉ is O or NR₁₇, wherein R₁₇ has the same meaning as defined above, R₁₀ and R′₁₀ are independently from each other H; halogen; unsubstituted C₁₋₂alkyl or —NO₂, R₁₁ is —SO₃H or —COOH, R₁₂ is H or halogen, R₁₃ is H; —SO₃H or halogen R₁₄ is H or halogen, R₁₅ is H or halogen, wherein the compound of formula (III) is

 wherein R₁₆ is H;

 —COC₁₋₂alkyl; —CO(CH₂O)_(n)—R₂₂; or —SO₂R₂₂, wherein R₂₂ is an unsubstituted phenyl or a phenyl moiety, which is substituted by at least one substituent selected from the group consisting of —CH₃ and halogen, n is 0 or 1, R₁₉ is H; —CH₃; —SO₃H or —OR₂₃, wherein R₂₃ is —CH₃; unsubstituted phenyl; substituted phenyl or benzyl R₂₀ is H; halogen; C₁₋₁₀alkyl or —NHCOCHBrCH₂Br R₂₁ is H; —NO₂; C₁₋₁₅alkyl or C₅₋₇cycloalkyl; wherein the compound of formula (IV) is

 wherein R₂₄ is H or —SO₃H, R₂₅ is H; —NHCOC₁₋₂alkyl or —OH, R₂₆ is H or —OH; R₂₇ is

 wherein R₂₈ is H or unsubstituted phenyl, R₂₉ is H; —COH; —NO₂;

 wherein R₃₀ is H or —CH₃, or R₂₇ is

wherein the compound of formula (V) is

wherein R₃₁ is H or

R₃₂ is

wherein R₃₃ is H; —SO₃H; —CF₃; —Cl; —COOC₁₋₂alkyl; or —SO₂R₃₆, wherein R₃₆ is unsubstituted phenyl; substituted phenyl; O-phenyl; —NH—C₁₋₁₂alkyl; —N(C₁₋₆alkyl)₂; unsubstituted C₅₋₈cycloalkyl; substituted C₅₋₈cycloalkyl; C₅₋₈cycloalkyl with at least one N, O or S atom incorporated into the ring;

R₃₄ is H; —NHCOC₁₋₄alkyl; —NHCOphenyl, wherein the phenyl ring is unsubstituted or substituted; —N(C₁₋₂alkyl)COC₁₋₄alkyl; —N(C₁₋₂alkyl)COphenyl, wherein the phenyl ring is unsubstituted or substituted; unsubstituted phenyl; substituted phenyl; O-phenyl, wherein the phenyl is unsubstituted or substituted; halogen; —SO₃H; —NHCOOC₁₋₂alkyl; —NHCOOC₅₋₇cycloalkyl, wherein the cycloalkyl is substituted or unsubstituted and —SO₂NHphenyl, wherein the phenyl ring is unsubstituted or substituted, R₃₅ is H; —NHCOC₁₋₄alkyl; —NHCOphenyl, wherein the phenyl ring is unsubstituted or substituted; —N(C₁₋₂alkyl)COC₁₋₄alkyl; —N(C₁₋₂alkyl)COphenyl, wherein the phenyl ring is unsubstituted or substituted; unsubstituted phenyl; substituted phenyl; O-phenyl, wherein the phenyl is unsubstituted or substituted; halogen; —Cl; —CH₃; —COOC₁₋₄alkyl and —SO₂NHphenyl, wherein the phenyl ring is unsubstituted or substituted.
 2. The composition according to claim 1 wherein the compound according to formula (II) is selected from the group consisting of C.I. (Colour Index) Acid Red 50, C.I. Acid Red 51, C.I. Acid Red 52, C.I. Acid Red 87, C.I. Acid Red 91, C.I. Acid Red 92, C.I. Acid Red 93, C.I. Acid Red 94, C.I. Acid Red 95, C.I. Acid Red 98, C.I. Acid Red 289 Acid Violet 9 and C.I. Acid Violet
 30. 3. The composition according to claim 1, wherein the compound of formula (II) Is Acid Red 52 or C.I. Acid Red
 289. 4. A recording fluid comprising a dye mixture according to claim
 1. 5. A recording fluid as claimed in claim 4, wherein the dye mixture is in desalted form.
 6. A recording fluid as claimed in claim 4, wherein the recording fluid is an ink-jet ink.
 7. A recording fluid according to claim 4, further comprising water or a medium including a mixture of water and an organic solvent, an anhydrous organic solvent or a solid having a low melting point.
 8. An electrophotographic toner comprising a dyestuff mixture according to claim
 1. 9. A method for dyeing or printing natural or synthetic fiber materials, for recording script and images on recording media, or for coloring paper or cellulose in the pulp, comprising the step of adding a dye mixture according to the claim 1 to said fiber material, recording media or pulp.
 10. An inkjet printing composition for printing recording materials comprising 1) the dye of formula (I)

 and 2) water or a medium including a mixture of water and an organic solvent, an anhydrous organic solvent or a solid having a low melting point.
 11. A printing method for printing a substrate with a printing ink comprising the step of adding to the printing ink a compound of formula (I)


12. The composition according to claim 1 wherein the compound according to formula (III) is selected from the group consisting of C.I. Acid Red 1, C.I. Acid Red 33, C.I. Acid Red 35, C.I. Acid Red 40, C.I. Acid Red 76, C.I. Acid Red 106, C.I. Acid Red 138, C.I. Acid Red 155, C.I. Acid Red 160, C.I. Acid Red 172, C.I. Acid Red 249, C.I. Acid Red 264 and C.I. Acid Red
 265. 13. The composition according to claim 1 wherein the compound according to formula (IV) is selected from the group consisting of C.I. Acid Red 15, C.I. Acid Red 19, C.I. Acid Red 29, C.I. Acid Red 60, C.I. Acid Red 68, C.I. Acid Red 154 and C.I. Acid Red
 176. 14. The composition according to claim 1, wherein the compound according to formula (V) is selected from the group consisting of C.I. Acid Red 30, C.I. Acid Red 34, C.I. Acid Red 37, C.I. Acid Red 42, C.I. Acid Red 54, C.I. Acid Red 57, C.I. Acid Red 231, C.I. Acid Red 266, C.I. Acid Red 301 and C.I. Acid Red
 337. 15. The method of claim 11, wherein the printing method is ink jet printing or electrophotographic printing. 